All online listings are probably out of date. People are quite keen to get their events publicised when they set them up to begin with, but rarely bother to get in touch when they move; and almost never notify when they stop.

If Southern events are missing from the map, that is because the people who run them haven't added them.

I've been running club and session listings for years, and many online and print resources exist for such; but accuracy depends on the people who organise or attend them taking the trouble to remember where they have placed details, and updating them when they change. Most of us don't have the time to contact everybody every few months to see what they are up to; and none of us, I think, are psychic; though we do keep an ear to the ground.